Process foe producing soap having



1938. B. CLAYTON Re. 20,772

PROCESS FOR PRODUCING SOAP HAVING A DEFINITE WATER CONTENT OriginalFiledvJrune 16. 1954 r/4 Z 35 36 6a z? WED 36 9 .7 62 a4 96 be A3 -I!-34 W M Z4 65 63 f/v vz/v TOR 55mm MIN (1/: Y TON ATTORNEY- Reissued June28, 1938 UNITED STATES PATENT OFFICE PROCESS FOR PRODUCING SOAP HAVING ADEFINITE WATER CONTENT Original No. 2,037,003, dated April 14, 1936,Serial No. 730,971, June 13, 1334. Application for re-. issue June 13,1337, Serial No. 143,312

18Claims.

My invention relates to the manufacture of soap and an object of theinvention is to provide a process of and apparatus by which soap may beproduced directly in a continuous process from raw material.

A further object of the invention is to provide a process of andapparatus for producing soap continuously in which the soap is producedin solid form of any suitable shape.

A further object of. the invention is to provide an apparatus for andprocess of producing soap in which the moisture content of the soapproduced can be accurately regulated within any desired limits. 1

Further objects and advantages will be made evident hereinafter.

Referring to the drawing, which is purely diagrammatic, is a mixingapparatus, 2 is. a heater, 3 is a separating chamber, 4 is an extrusionpump, 5 is a boiler, 3 is a cooler and extruder, I is a water injectionpump, 3 is a glycerine condenser, and 3 is a water condenser of the Jettype.

The mixing apparatus consists of an alkali pump II and a fat pump l2,the pump l2 being driven by a suitable motor 3 and the pump being driventhrough a speed changing gear M from the pump l2. The fat which it isdesired to convert into soap is taken from a fat tank l3 and pumped intoa mixer H by the pump I2. An alkali tank |3 contains an aqueous solutionof a saponifying alkali such, for example, as caustic soda in water, thepump taking the aqueous alkali solution or reagent from the tank It andpumping it into the mixer H. The mixed fat and reagent pass through apipe l3 to a coil 2| of the heater 2.

The heater 2 consists of an outer shell 23 in which a coil 2| is placed,and a burner 24 supplied with fuel through a fuel valve 25. Gas or oilmay be used as fuel, this fuel being ignited at the burner and the hotproducts of combustion passing upwardly inside the shell 23 andsupplying heat to the coil 2|. In the coil 2| a reaction takes placebetween the reagent and the fat, soap, glycerine and water vapors,hereinafter termed the "reaction products, being delivered through apipe 23, havihg a pressure gauge 21 and a-thermor'neter 23 therein, to anozzle 3| in the separating chamber 3.

The separating chamber 3 consists of a tight shell 32 inside which thenozzle 3| is carried. The nozzle consists of a metal member having aconstricted orifice through which the reaction products must pass. Thesoap pump 4 is preferably a gear or screw pump capable of handling thehot soap precipitated in the chamber 32. This pump is driven by a motor3| and delivers the hot soap to a pipe 32.

The boiler 3 may be of any convenient type, 5 that shown consisting of ashell II in which is placed a pipe coil 32. The water in the pipe coil32 is heated by the products of combustion from a burner 53 suppliedwith gas through a fuel valve 34. Steam is delivered from the boiler 3through a pipe 33, having a thermometer l3 and a pressure gauge 31therein, to the pipe 42.

While diil'erent forms of cooler 3 may be employed, it is desirable thatone be used which tends to uniformly mix the steam delivered by 13 thepipe 33 with soap delivered from the pipe 42 and the form shown is welladapted to accomplish this result. It consists of a tight shell 3| inwhich is placed a coil 32 into which the mixture of soap and steam isdelivered by the pipe 42. The cooled soap leaves the coil 32 through apipe 33. Cooling water is supplied to the cooler 3 through a pipe 33,the flow being controlled by a valve 33. Hot water is delivered from thecooler 3 through a pipe 33 to a tank 31. The cooled soap is deliveredthrough the pipe 33 to an extrusion nozzle 33, which may have a singleor several orifices of any desired shape, the soap being extruded in theform of threads or as a continuous bar 33. Devices may be incorporatedin the extrusion nozzle 33 to break up the threads or bar into separatepieces of soap or the threads or bar 33 may be broken up after leavingthe extrusion nozzle 33.

The water injection pump I may also be a 35 screw or gear pump, beingdriven by a motor 1|, the speed of which may be regulated to control theamount of water injected through a pipe 12 into the coil 32 of theboiler 3.

Any gas or vapor released in the separating chamber 3 is withdrawnthrough a pipe 33 having a pressure gauge 35 and a thermometer 33therein. The pipe 34 communicates with the bottom of the glycerinecondenser 3. The glycerine condenser 3 consists of a tight shell 3|having in- 43 termediate heads 32 between which tubes 33 extend. Thespace between the heads 32 inside the shell 3| and around the tubes 33is filled with cooling water delivered through a pipe 33 having a valve35, this cooling water being removed 30 through a pipe 33.

Any condensate produced in the glycerine condenser 3 passes downwardlythrough a pipe 31 to a glycerine tank 33, the pipe 31 being about thirtyfeet long so that as long as the lower end of the 33 pipe is submergedin the'glycerine in the tank 98, it is possible to maintain a highdegree of vacuum in the condenser 9.

Any gases or vapors which are not condensed in the glycerine condenser 9pass through a pipe 9|, having a thermometer 92 and a pressure gauge 99therein, to thejet condenser 9. This jetcondenser is supplied withcooling water from a pipe 94 and is provided with an air pump 95. Anywater condensed in the jet condenser 9 is delivered through a pipe 98 toa water tank 91. The pipe 99 is about thirty feet long so that as longas the lower end is submerged in the water in the tank 91, a vacuum maybe maintained in the condenser 9 if desired.

The method of operation is as follows:

The tank I6 is filled with the saponifiable fat which it is desired toconvert into soap, this fat being warmed if necessary to a point atwhich it is liquid. The tank I9 is filled with an aqueous solution of asaponifying alkali, such, for example, as a solution of caustic soda inwater. The fat is pumped into the mixer I1 by the pump 12 and thesaponifying alkali is pumped into the mixer I! by the pump H. Thevariable speed gear I is adjusted so that the proportion of saponifyingalkali supplied to the mixer I1 is only slightly in excess of thattheoretically necessary to completely saponify the fat. The pumps II andI2 may be piston pumps but should be of such type that they can pumpagainst several hundred pounds per square inch pressure. The mixture ofsaponiilable fat and saponfying alkali is delivered through the pipe i9to the heater 2 and is heated therein by the products of combustion fromthe burner 24.

It will be understood that the aqueous solution of a saponiiying alkaliis dispersed in the saponiilable material due to mixing in the mixer l1and is maintained in dispersion during the flow of the material throughthe coil 2| of the heater. The reagent or aqueous solution of asaponifying alkali is in the form of fine drops, the surfaces oi whichare in contact with the oil. of producing a reaction between the reagentand the saponifiable material by providing contact between the reagentand the oil is for convenience termed contacting."

In the coil 2| a reaction takes place between the saponifying alkali andthe saponifiable fat, and soap and glycerine are formed. Sumcient heatis supplied to the mixture in the coil 2| to raise the temperature ofthe reaction products passing through the pipe 26, as indicated on thethermometer 29.

The reaction products, that is to say, the soap and glycerine, with allof the water content of the mixture delivered to the coil 2|, areejected through the nozzle 3| into the separating chamber 3. Theinterior of the separating chamber 3 is maintained under vacuum andthere is, of course, a high pressure drop as the reaction products passthrough the constricted orifice of the nozzle 9i.

These reaction products emerge from this constricted orifice in the formof a high velocity jet containing steam, glycerine vapor, and particiesof liquid soap. The soap is thrown violently downward to the bottom ofthe chamber due to the velocity of the jet and in its passage throughthe chamber the glycerine vapor and steam escape therefrom, passingupwardly and being withdrawn through the pipe 34. Suflicient heat shouldbe supplied by the burner 24 to enable the temperature as indicated bythe ther- This method mometer 39 of the vapors passing to the glycerinecondenser 9 to be maintained above the boiling point of glycerine at theabsolute pressure indicated on the vacuum gauge 95.

The soap which is delivered to the bottom oi the separating chamber 3contains almost no water or glycerine. It is, however, at a sumcientlyhigh temperature to be liquid and it is continuously withdrawn throughthe soap pump 4 and delivered to the pipe 42.

Since the soap delivered to the pump 4 is practically free from water,it is desirable to add water thereto to produce a commercial soap, sincesuch soaps usually contain from 10% to 20% of water. Thiswater contentis added in the form of steam injected through the pipe I5 into theflowing stream of hot soap leaving the pump 4 through the pipe 42. Thepump 4 should be capable of exerting considerable pressure since it notonly takes soap from the chamber, which is under a vacuum, and extrudesit against atmospheric pressure, but it must also overcome some fluidfriction in the cooler 6 and a very considerable friction in theextrusion nozzle 89. By regulating the rate of feed of the water pump Iin proportion to the rate of feed of the fat pump II, a soap ofabsolutely fixed and definite water content can be produced.

The mixture of steam and glycerine vapor passing through the pipe 94into the glycerine condenser 8 is cooled in its upward passage throughthe tubes 89 to such a degree that substantially all of the glycerinecontent of these vapors is condensed, this glycerine condensate runningdownwardly through the pipe 91 to the tank 89. The steam, freed from theglycerine vapors, then passes through the pipe 9| to the water condenser9. The supply or cooling water delivered to the glycerine condenserthrough the pipe 84 is so regulated that the temperature of the steampassing through the pipe 9|, as indicated on the thermometer 92, isconsiderably below the boiling point of glycerine at the pressureindicated on the pressure gauge 93 and above the boiling point of waterat that pressure.

In the jet condenser 9 the steam is condensed due to the introduction ofcooling water through the pipe 94, the condensed water being deliveredthrough the pipe 96 to the tank 9'I.- Any air or uncondensed vapor orgas which would tend to accumulate in the jet condenser 9 iscontinuously withdrawn by the air pump 95.

In practice the degree of vacuum carried in the separating chamber 3 maybe regulated by suitable manipulation of the condensers 9 and 9 and theair pump 95. The degree of vacuum maintained depends somewhat upon thetempperature of the jet leaving the nozzle'3l. The higher thistemperature, the higher the absolute pressure can be carried in theseparating chamher 3. This pressure must be suiliciently low to promotea rapid vaporization of the glycerine, this vaporization being promotedby the fact that the chamber also contains steam, thus reducing thepartial pressure of the glycerine vapors due to the law of partialpressures.

In practice the apparatus operates continuously, the tanks i6 and I9being replenished from time to time and the glycerine and waterdelivered to the tanks 91 and 88 being withdrawn as they accumulate. Thesoap 69 extruded from the pipe 6| has a definite and constant watercontent. The glycerine recovered, being a distillate, is in very pureform and has a high commercial value.

If desired, the temperature in the separating chamber! can be loweredsumciently so that all or a portion of the glycerine is not vaporizedand is carried over as a liquid in the soap removed by the pump '4. Thesame eiiect can, of course, be obtained by increasing the absolutepressure in the separating chamber. All that is necessary to permit theglycerine to be carried over into the soap with asubstantial dehydrationof. the soap passing to the pump 4, is to hold the temperature in theseparating chamber 3 above the boiling point oi water at the pressuremaintained therein, but below the boiling point of glycerine under thatpressure.

I claim as my invention:

1. A continuous process of producing soap directly from a saponiflablematerial by the reaction therewith of an aqueous solution of asaponiiying reagent, and recovering the glycerine pro duced by theprocess, which comprises: contacting the materials to produce soap andglycerine; continuously passing the mixture of soap and glycerine intoan evaporating chamber; continuously removing water and glycerine vaporfrom said chamber at a rate suiiicient to maintain a sumcient vacuumtherein to vaporize substantially all the water and glycerine in saidmixture; and continuously withdrawing soap from said chamber in such amanner as not to impair the vacuum maintained therein.

2. A continuous process of producing soap directly from a saponifiablematerial by the reaction therewith oi an aqueous solution of asaponifying reagent, and recovering the glycerine produced by theprocess, which comprises: contacting the materials to produce soap andglycerine; continuously passing the mixture of soap and glycerine intoanevaporating chamber; continuously removing water and glycerine vaporfrom said chamber at a rate suflicient to'maintain a sufllcient vacuumtherein to vaporize substantially all the water and glycerine in saidmixture; maintaining the soap at such, a temperature after the glycerineand water vapor has been withdrawn therefrom that it is molten andsufilciently liq- .uid to be pumped; and pumping said soap out of saidchamber as the soap is formed therein without impairing the vacuummaintained in said chamber.

3. A continuous process of producing soap directly from a saponifiablematerial by the reac-- tion therewith oi an aqueous solution of asaponiiying reagent, and'recovering the glycerine produced by theprocess, which comprises: contacting the materials to produce soap andglycerine; continuously passing the mixture of soap and glycerine intoan evaporating chamber; continuously removing water and glycerine vaporfrom said chamber at a rate suflicient to maintain a suflicient vacuumtherein to vaporize substantially all the water and glycerine in saidmixture; maintaining the soap at such a temperaure after the glycerineand water vapor has been withdrawn therefrom that it is molten andsufliciently liquid to be pumped; pumping said soap out of said chamberas the soap is formed therein without impairing the vacuum maintained insaid chamber; cooling said soap after it has been so pumped toatemperature at which it is plastic: and utilizing the pressure used forpumping the soap from said chamber to extrude the soap from a suitableorifice in the form of a 'solid bar.

4. A continuous process of producing soap directly from a saponifiablematerial by the reaction therewith of an aqueous solution o1 asaponitying reagent, and recovering the glycerine produced by theprocess, which comprises: contacting the materials to produce soap andglycerine; continuously passing the mixture of soap and glycerine intoan evaporating chamber; continuously removing water and glycerinevaporirom said chamber at a rate sufllcient to maintain; a suiflcientvacuum therein to vaporizesubstantially all the'water and glycerine insaid mixture; continuously withdrawing soap from said chamber in such amanner as not to impair the vacuum maintained therein; and addingsuflicient water to said soap after it has been withdrawn from saidchamber to give it a definite water content. 5. A continuous process ofproducing soap directly from a saponiflable material by the reactiontherewith of an aqueous solution of a saponifying reagent, andrecovering the glycerine pro duced by the process, which comprises:contactingithe materials to produce soap and glycerine; continuouslypassing the mixture of soap and glycerine into an evaporating chamber;continuously removing water and glycerine vapor from said chamber at arate suflicient to maintain a suiilcient vacuum therein to vaporizesubstantially all the water and glycerine in said mixture; maintainingthe soap ,at such a temperature after the glycerine and water vapor hasbeen withdrawn therefrom that it is molten and sufficicntly liquid to bepumped; pumping said soap out of said chamber as the soap is formedtherein without impairing the vacuum maintained in said chamber; andadding sufllcient water to said soap after it has been withdrawn fromsaid chamber to give it a definite water content.

6. A continuous process of producing soap directly from a saponifiablematerial by the reaction therewith of an aqueous solution of asaponilying reagent, and recovering the glycerine produced by theprocess, which comprises: contacting the materials to produce soap andglycerine; continuously passing the mixture of soap and glycerine intoan evaporating chamber; continuously removing water and glycerine vaporfrom said chamber at a rate sufiicient to maintain a sufficient vacuumtherein to vaporize substantially all the water and glycerine in saidmixture;

maintaining the soap at such a temperature after the glycerine and watervapor has been withdrawn therefrom that it is molten and sumcientlyliquid to be-pumped; pumping said soap out of said. chamber as the soapis formed therein without impairing the vacuum maintained in saidchamber; cooling said soap after it has been so pumped to a temperatureat which it is plastic; i

adding sufiicient water to said soap after it has been withdrawn fromsaid chamber to give it a definite water content; and utilizing thepressure used for pumping the soap from said chamber to extrude the soapfrom a suitable orifice in the form of a solid bar.

7. A process of producing soap directly from a saponifiable material bythe reaction therewith of an aqueous solution of a saponiiying reagentand recovering the glycerine produced by the process, which comprises;contacting the materials to produce soap and glycerine; continuouslypassing the mixture of soap and glycerine into an evaporating chamber;continuously removing water and glycerine vapor from said chamber at arate sufiicient to maintain a sufiicient vacuumtherein to vaporizesubstantially all the water and glycerine in said mixture; andcontinuously withdrawing soap from said chamber in such a manner as notto impair the vacuum maintained therein.

8. A process of producing soap directly from a saponifiable material bythe reaction therewith oi an aqueous solution of a saponifying reagentand recovering the glycerine produced by the process, which comprises:contacting the materials to produce soap and glycerine; continuouslypassing the mixture of soap and glycerine into an evaporating chamber;continuously removing water and glycerine vapor from said chamber at arate sufilcient to maintain a sufllcient vacuum therein to vaporizesubstantially all the water and glycerine in said mixture; maintainingthe soap in said chamber at such a temperature after the glycerine andwater has been withdrawn that it is molten; and continuously withdrawingsoap from said chamber in such a manner as not to impair the vacuummaintained therein.

9. A process of producing soap directly from a saponiflablematerial bythe reaction therewith of an aqueous solution 01' a saponifying reagent,and recovering the glycerine produced by the process, which comprises:contacting the materials to produce soap and glycerine; continuouslypassing the mixture of soap and glycerine into an evaporating chamber;continuously removing water and glycerine vapor from said. chamber at arate suilicient to maintain a suflicient vacuum therein to separate asvapor substantially all the water and glycerine in said mixture:maintaining the soap at such a temperature after the glycerine and watervapor has been withdrawn therefrom that it is molten and sumcientlyliquid to be pumped; and pumping said soap out oi. said chamber as thesoap is formed therein without impairing the vacuum maintained in saidchamber.

10. A process of producing soap and recovering glycerine therefrom,which comprises the steps of reacting a saponifiable material with asaponifying reagent to effect substantial saponification, thereafterpassing the resultant saponifled mixture, including soap and glycerine,into a vapor separating chamber and there promoting the separation ofglycerine vapors from the soap by aintaining a temperature sumcientlyhigh to cause the separated soap to be in a substantially liquidcondition in said chamber, withdrawing the glycerine vapors from saidvapor separating chamber at a rate suiiicient to maintain a vacuum insaid chamber, withdrawing the substantially liquid soap from said vaporseparating chamber without substantially impairing the said vacuummaintained therein.

11. The process of producing soap and recovering glycerine whichincludes the steps 01' continuously withdrawing glycerine vapors from anevaporating chamber containing a mixture of soap and glycerine, at arate sufllcient to cause a reduced pressure to be maintained therein,promoting the separation of glycerine vapors from said soap bymaintaining sufiicient temperature in said evaporating chamber to causethe soap therein to be in a liquid condition when said vapors areseparated from said soap, and withdrawing the liquid soap from saidchamber without substantially impairing the reduced pressure maintainedtherein.

12. The process of producing soap and removing vaporizable impuritiestherefrom which comprises the steps of mixing saponifiable andsaponifying materials, advancing the mixture, under pressure, to anevaporating chamber, heating the mixture to a temperature suflicient tovaporize said impurities when said pressure is reduced, discharging theheated mixture into thesaid some evaporating chamber, continuouslywithdrawing vapors from said chamber at a rate suiiicient to maintain avacuum therein, maintaining the soap in a substantially liquid conditionuntil removed from said chamber and removing'said soap from said chambersubstantially as soon as the same collects therein without substantiallyimpairing the vacuum maintained in said chamber and during theconcurrent introduction of the mixture to the evaporating chamber.

- 13. The process 01 producing soap and removing therefrom vaporizableimpurities which comprises the steps of admixing saponiflable andsaponifying materials to effect substantial saponification, introducingsaid mixture into an evaporating chamber, maintaining a temperature uponsaid mixture sufllcient to vaporize the vaporizable constituents thereofand to maintain the soap in said chamber in a molten condition untilremoved, withdrawing the vaporized constituents at a rate suflicient tomaintain a vacuum in said chamber, and withdrawing the molten soap iromthe chamber without breaking the vacuum main tained therein.

14. The process of producing soap and removing vaporizable impuritieswhich includes the steps of continuously withdrawing the vaporizableimpurities from an evaporating chamber containing a mixture of soap andvaporizable impurities, at a rate suflicient to cause a reduced pressureto be maintained therein, and continuously withdrawing the soap fromsaid chamber without substantially impairing the reduced pressuremaintained therein.

15. The process of producing soap and removing vaporizable-impuritlestherefrom which comprises the steps of pumping under pressure a streamof previously saponified soap and said impurities to a vapor separatingchamber, heating the stream during its advancement to an extentsufliciently high to vaporize said impurities during the advancement ofsaid stream, introducing the thus heated stream to an evaporatingchamber maintained under a vacuum whereby said impurities are separatedas vapors from said soap, continuously withdrawing the soap while thestream is being continuously introduced to the'vapor separating chamber.

16. The process as defined in claim 15 in which the impurities areseparated as vapors with the aid of steam functioning to reduce thepartial pressure of said vapors.

17. A continuous process for producing soap and recovering glycerinewhich comprises the steps of pumping together saponifiable andsaponifying materials, advancing the resultant mixture as a streamthrough a reaction zone to eifect substantial saponification and theformation of glycerine, supplying suflicient heat to the mixture as itis continuously advanced through said reaction zone to vaporize at leasta portion of said glycerine, continuously introducing the mixture oisoap and glycerine thus produced into an evaporating chamber,continuously withdrawing the glycerine vapor from said chamber at a ratesufficient to maintain a partial vacuum therein, maintaining the soap atsuch a temperature after the glycerine has been removed therefrom thatit is in a substantially molten condition, continuously withdrawing thesaid molten soap in its anhydrous and substantially glycerine free statefrom the evaporating chamber without substantially impairing the partialvacuum therein maintained and continuously subjecting the soap aftermaterials in said zone to cause substantially complete vaporization oisaid vaporlzable materials when said mixture is introduced into a vaporp rating chamber. introducing the mixture to said chamber, continuouslywithdrawing said vapors from said chamber at a rate suincient tomaintain a vacuum in said chamber and withdrawing the soap from thevapor separating chamber without substantially impairing the said vacuummaintained therein.

ENJAMIN CLAYTON.

